xfs: fix up build warnings when quotas are disabled

Fix some build warnings on gcc 10.2 when quotas are disabled.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>

fs/xfs/xfs_quota.h

@@ -130,7 +130,7 @@ xfs_qm_vop_dqalloc(struct xfs_inode *ip, kuid_t kuid, kgid_t kgid,
 }
 #define xfs_trans_dup_dqinfo(tp, tp2)
 #define xfs_trans_free_dqinfo(tp)
-#define xfs_trans_mod_dquot_byino(tp, ip, fields, delta)
+#define xfs_trans_mod_dquot_byino(tp, ip, fields, delta) do { } while (0)
 #define xfs_trans_apply_dquot_deltas(tp)
 #define xfs_trans_unreserve_and_mod_dquots(tp)
 static inline int xfs_trans_reserve_quota_nblks(struct xfs_trans *tp,
@@ -166,8 +166,8 @@ xfs_trans_reserve_quota_icreate(struct xfs_trans *tp, struct xfs_dquot *udqp,
 #define xfs_qm_dqattach(ip)						(0)
 #define xfs_qm_dqattach_locked(ip, fl)					(0)
 #define xfs_qm_dqdetach(ip)
-#define xfs_qm_dqrele(d)
-#define xfs_qm_statvfs(ip, s)
+#define xfs_qm_dqrele(d)			do { (d) = (d); } while(0)
+#define xfs_qm_statvfs(ip, s)			do { } while(0)
 #define xfs_qm_newmount(mp, a, b)					(0)
 #define xfs_qm_mount_quotas(mp)
 #define xfs_qm_unmount(mp)